There are two 100MB/s ports on the kit, eth0 & eth1.
$ ifconfig (to get the IP address) $ iperf3 -s
$ iperf3 -c <IP_ADDRESS_OF_IPERF_SERVER> -u -b 100M
2 Using only one Ethernet port
To remove the second Ethernet port, in case your own custom carrier board only has one and doesn't have the second Ethernet phy:
Edit the dtsi file of the reference carrier board in the Linux kernel source and remove the &fec1 and &fec2 nodes from it.
In case of the VAR-6ULCustomBoard (DART-6UL carrier), the file is arch/arm/boot/dts/imx6ul-imx6ull-var-dart-6ulcustomboard.dtsi.
In case of the Concerto-Board (VAR-SOM-6UL carrier), the file is arch/arm/boot/dts/imx6ul-imx6ull-var-som-concerto-board.dtsi.
The above will result in using the &fec1 node from the dtsi file of the SOM, as is (as the phy of the first Ethernet port is on the SOM), without adding the second port (which its phy is on the reference carrier board).
- You can follow the "Build Linux from source code" guide to get the Linux kernel source, apply the above patch, build only the device trees and copy them to your SD card.